This application is based on and incorporates herein by reference Japanese Patent Applications No. 2000-296345 filed Sep. 28, 2000 and No. 2000-357684 filed Nov. 24, 2000.
The present invention relates to a vehicle-mounted device control system mounted in a passenger vehicle, a truck or the like, and particularly to a power generator control system which enables use of a single electronic control unit even when a power generator type is changed.
Electric power generated by a power generator (alternator) mounted in a vehicle is used to drive various electric loads and to charge a vehicle-mounted battery. The output current characteristic and the torque characteristic of the power generator are determined in accordance with a vehicle type and vehicle-mounted electric loads. These characteristics differ by types of vehicles. Further, the characteristics differ for the same type of vehicle, when a maker of a power generator differs.
When the output current characteristic and the torque characteristic of a power generator differ, it is necessary to change control constants of an electronic control unit for controlling other vehicle-mounted devices in accordance with operation characteristics of a power generator. As a result, it is necessary to provide various types of electronic control units in vehicles in correspondence with the types of power generators.
It is therefore an object of the present invention to provide a vehicle-mounted device control system capable of reducing the number of necessary types of electronic control units and power generators.
According to the present invention, a vehicle-mounted control system comprises a vehicle-mounted device such as a power generator controllable in response to a control signal applied thereto, an electronic control unit for controlling the vehicle-mounted device by outputting the control signal, and a communicating line for transmitting the control signal from the electronic control unit to the vehicle-mounted device. The electronic control unit automatically changes the control signal in response to a change in a type of the vehicle-mounted device.